Noah Webster’s 1828 Dictionary
X - XYSTER
X, the twenty fourth letter of the English Alphabet, is borrowed from the Greek. In the middle and at the end of words, it has the sound of ks, as in wax, lax, luxury. At the beginning of a word, it has precisely the sound of z. It is used as an initial, in a few words borrowed from the Greek.
As a numeral, X stands for ten. It represents one V, which stands for five, placed on the top of another. When laid horizontally it stands for a thousand, and with a dash over it, it stands for ten thousand. As an abbreviation, X. Stands for Christ, and in Xn. Christian; Xm. Christmas.
XANTHOGENE, n. [Gr., yellow, to generate.] The base of a new acid, produced by the mixture of a solution of pure potassa with bisulphuret of carbon. This acid contains sulphur, carbon, and hydrogen. It is named from the yellow color of its compounds.
XEBEC, n. A small three masted vessel, used in the Mediterranean sea. With a fair wind, in good weather, it carries two large square sails; when close hauled, it carried large lateen sails.
XEROCOLLYRIUM, n. [Gr., dry.] A dry collyrium or eye-salve.
XEROMYRUM, n. [Gr., dry; ointment.] A dry ointment.
XEROPHAGY, n. [Gr., dry; to eat.] The eating of dry meats, a sort of fast among the primitive Christians.
XEROPHTHALMY, n. [Gr., dry.] A dry red soreness or itching of the eyes, without swelling or a discharge of humors.
XIPHIAS, n. [Gr., a sword.]
1. The sword-fish.
2. A comet shaped like a sword.